A short-process high-efficiency low-cost electric furnace automatic power supply method, smelting process and smelting system for high-carbon steel wire rods

Abstract

The present application relates to a kind of high carbon steel wire short process high-efficiency low-cost electric furnace automatic power supply method, smelting process and smelting system, waste steel melting condition is monitored dynamically by pull rope encoder, and electric furnace smelting stage is divided into wear period, melting period, temperature rise period and temperature composition adjustment period by comprehensively considering waste steel melting condition and smelting power consumption condition;According to the division of electric furnace smelting stage, the voltage gear of each stage, the current gear is set, so as to realize the accurate efficient control of electric furnace smelting process, improve the electric arc energy utilization, speed up the melting of waste steel, improve the smelting efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to a high-carbon steel wire short-process efficient low-cost electric furnace automatic power supply method, smelting process and smelting system, belonging to the technical field of smelting process, especially about electric furnace short-process smelting process. BACKGROUND

[0002] In the existing high-carbon steel wire smelting process, the quality fluctuation of raw materials such as iron ore may affect the stability of product quality. With the long-term development of the steel industry, a large amount of scrap steel resources has accumulated in society. When the supply of scrap steel is stable and the price is competitive, enterprises find that the electric furnace short-process process using scrap steel as the main raw material is more attractive.

[0003] The scrap steel used in the electric furnace short-process is relatively clear in composition, and under the cooperation of the accurate batching system, the quality of the raw materials can be more easily controlled, thereby ensuring the consistency of the product quality of the high-carbon steel wire. At the same time, the electric furnace short-process process has a fast heating speed and a short smelting period, which can complete the production of high-carbon steel wire faster than the traditional process, greatly improving the production efficiency and market competitiveness of the enterprise.

[0004] For the electric furnace smelting process, the radiation energy generated by the electric arc during power-on is the main source of scrap steel melting, so a reasonable power supply system is of great significance to improve the smelting efficiency and reduce the smelting power consumption. In the electric furnace smelting process, the power supply system is mainly adjusted by adjusting the transformer voltage gear and the electric arc current gear, and this operation is basically based on the experience of the furnace master to execute. Patent CN109136462A provides an electric arc furnace smelting power supply method, which mainly relies on the change of power supply time to set the transformer gear. Patent CN115537495A provides a power supply process for a large-scale alternating current electric arc furnace, in which a reasonable power supply system is formulated by different electricity prices and ton steel profit states, thereby realizing the best economic benefit of the electric arc furnace smelting. Patent CN116837176A provides an efficient power supply method and system for the electric furnace smelting process, which adjusts the power supply system according to the noise change in different stages of the electric arc furnace smelting process.

[0005] However, in the electric furnace smelting power supply process, the real-time melting state of the scrap steel in the furnace and the reaction in the furnace are crucial to the selection of the power supply system. The above-mentioned several patents fail to realize real-time feedback of the situation in the furnace, so it is impossible to guarantee whether the formulated power supply system can meet the actual needs of the electric furnace smelting. SUMMARY

[0006] In order to solve the problems in the background art, the present application provides a high-carbon steel wire short-process efficient low-cost electric furnace automatic power supply method, a smelting process and a smelting system, which can realize optimized power supply of electric furnace smelting, shorten the power supply time and reduce the smelting power consumption.

[0007] The technical scheme adopted by the present application to solve its technical problems is:

[0008] A high-carbon steel wire short-process efficient low-cost electric furnace automatic power supply method, when the molten iron passes through the KR treatment process, the following steps are continued:

[0009] Step S1, from the database, determine the weight of the scrap steel entering the furnace, the weight of the molten iron entering the furnace, the silicon content of the molten iron entering the furnace, the end composition of the smelted steel grade and the end temperature in the electric furnace process;

[0010] Step S2, calculate the required power supply in the electric furnace process through the weight of the molten iron entering the furnace, the end tapping temperature of the electric furnace and the silicon content of the molten iron entering the furnace, and the calculation formula is

[0011] is the power supply, unit: kWh, is the weight of the molten iron entering the furnace, unit: t is the end tapping temperature of the electric furnace, unit: ℃, is the silicon content of the molten iron entering the furnace, unit: %;

[0012] Step S3, start the electric furnace to begin smelting, through the change of the height of the electrode, and combined with the measured smelting power consumption, the electric furnace smelting process is sequentially divided into four periods, which are the drilling period, the melting period, the temperature rising period and the temperature composition adjustment period, the power supply curve is set, and the voltage and current of the four periods are adjusted;

[0013] Among them, after entering the temperature composition adjustment period, the first temperature sampling is carried out, the temperature T1 and the composition C1 are measured and obtained, based on the end composition and the end temperature of the smelted steel grade determined in step S1, the temperature composition adjustment period is adjusted according to the power supply curve, and the feeding is also adjusted at the same time, so that the end composition and the end temperature reach the tapping standard.

[0014] Further, in step S3, the time period from the start of power supply to the lowest point of the electrode height is defined as the drilling period, the time period from the end of the drilling period to the time period when the electrode maintains the same height is defined as the melting period, the time period from the end of the melting period to the time period when the power consumption is 85% of the required power supply is defined as the temperature rising period, and the time period from the end of the temperature rising period to the smelting end is defined as the temperature composition adjustment period.

[0015] ​​The smelting end point temperature is greater than or equal to 1600 DEG C, and the end point composition includes, in mass percentage, C > 0.04%, P < 0.012%, S < 0.012%, and N < 50 ppm;

[0016] Further, during the well penetration period, the transformer voltage gear is 10-12 gears, the current gear is 5-7 gears, the secondary side voltage is controlled at 713V-835V, and the arc length is controlled at 478mm-512mm.

[0017] Further, during the melting period, the transformer voltage gear is 14-15 gears, the current gear is 7-9 gears, the secondary side voltage is controlled at 871V-900V, and the arc length is controlled at 552mm-604mm.

[0018] Further, during the temperature rising period, the transformer voltage gear is 13-14 gears, the current gear is 8-9 gears, the secondary side voltage is controlled at 843V-871V, and the arc length is controlled at 529mm-562mm.

[0019] Further, during the temperature composition adjustment period, the transformer voltage gear is 12-13 gears, the current gear is 8-9 gears, the secondary side voltage is controlled at 815V-843V, and the arc length is controlled at 494mm-529mm.

[0020] Further, in step S1, the chemical composition of the scrap steel entering the furnace includes, in mass percentage, S ≤ 0.005%, Ni ≤ 0.01%, Cr ≤ 0.03%, Cu ≤ 0.01%, Al ≤ 0.01%, and Ti ≤ 0.01%.

[0021] Further, in step S1, the electric furnace loading amount is controlled in the range of 115t-118t, and the molten iron ratio entering the furnace is controlled in the range of 25%-50%.

[0022] Further, in step S3, the oxygen consumption of the electric furnace smelting process is in the range of 35-38Nm 3 / t, and the lime consumption is in the range of 30-35kg / t.

[0023] A high-carbon steel wire rod short-process high-efficiency low-cost smelting process, after using the electric furnace automatic power supply method, the following steps are continued:

[0024] In step S4, when the electric furnace tapping is to one-third, a low-nitrogen carbon additive is added, and a deoxidizer is added for pre-deoxidization, and after the tapping is completed, the ladle is lifted into the LF refining station for further adjustment of the temperature and composition, and the molten steel temperature range is controlled.

[0025] In step S5, after the composition adjustment in step S4 is completed, the ladle bottom argon blowing is adjusted to a soft stirring state to remove inclusions.

[0026] Step S6, using big billet continuous casting machine pouring, continuous casting whole process protection pouring; two cold section using weak cold mode, and set two cold section water 1 section for 60 NL / min -100 NL / min, 2 section for 20 NL / min -50 NL / min, 3 section for 20 NL / min -40 NL / min, 4 section for 10 NL / min -30 NL / min;

[0027] Step S7, cogging process, cogging into 140mm×140mm;

[0028] Step S8, high line rolling process;

[0029] Further, in step S4, the deoxidizer includes metal manganese and low titanium low aluminum ferrosilicon, after the component adjustment is completed, the molten steel temperature range is controlled to be 1525℃-1535℃;

[0030] In step S5, the flow rate of the ladle bottom argon blowing is set to be 60NL / min -110NL / min, and the soft stirring time is set to be 26min -31min;

[0031] In step S6, when the continuous casting whole process protection pouring is used, a low basicity low alumina intermediate ladle covering agent is used, the intermediate ladle molten steel superheat range is controlled to be 20℃-30℃, a low melting point crystallizer protection slag is used, and a crystallizer electromagnetic stirring is used; the crystallizer water quantity is set to be 2975 L / min -3025L / min;

[0032] In step S7, the cogging heating temperature range is set to be 1180℃-1250℃;

[0033] In step S8, when the high line rolling is used, the heating temperature is 1080℃-1160℃, the opening rolling temperature is 960℃-1030℃, and the wire drawing temperature is 860℃-920℃;

[0034] A high-carbon steel wire short-process high-efficiency low-cost smelting system for the high-carbon steel wire short-process high-efficiency low-cost electric furnace automatic power supply method, comprising an electrode, a pull rope encoder and an electric energy meter;

[0035] The electrode is fixed on the electrode cross arm through the electrode clamp, the electrode cross arm is driven connected with the electrode lifting hydraulic cylinder, and the pull rope of the pull rope encoder is installed on the hydraulic cylinder. When the electrode moves up and down in the electric furnace, the pull rope encoder can measure the height change of the electrode in real time;

[0036] The electric energy meter is installed on the power supply line of the ladle, which can measure the current, voltage and power of the ladle, and then calculate the power consumption;

[0037] By the above technical scheme, compared with the prior art, the present application has the following beneficial effects:

[0038] 1. The high-carbon steel wire short-process efficient and low-cost electric furnace automatic power supply method provided by the present application can make the error between the predicted power supply value and the actual required power supply value as small as possible, so as to more accurately determine the appropriate power supply according to various input conditions in the production process, avoid the influence of insufficient power supply on smelting efficiency, or the waste of energy caused by excessive power supply.

[0039] 2. The high-carbon steel wire short-process efficient and low-cost electric furnace automatic power supply method provided by the present application can accurately control the power supply according to the characteristics of each stage, improve the utilization of electric arc energy, speed up the melting of scrap steel, and improve the smelting efficiency.

[0040] 3. The high-carbon steel wire short-process efficient and low-cost smelting process provided by the present application is based on the electric furnace automatic power supply method, realizes dynamic analysis of the electric furnace smelting process, and realizes efficient and accurate automatic control of the high-carbon steel smelting process by combining real-time monitoring and identification of different stages.

[0041] 4. The high-carbon steel wire short-process efficient and low-cost smelting system provided by the present application can more accurately divide the electric furnace smelting stage by dynamically monitoring the electrode lifting hydraulic cylinder through the pull rope encoder to reflect the melting condition of scrap steel. DETAILED DESCRIPTION

[0042] The specific dimensions used in the embodiments are only for illustration of the technical scheme and do not limit the protection scope of the present application.

[0043] High-performance high-quality high-carbon steel wire products such as cord steel and spring steel have very high requirements for cleanliness, segregation, decarburization, surface quality, etc. The traditional blast furnace-converter long-process technology consumes a large amount of coke and other fuels, and the energy consumption is high. The electric furnace short-process mainly uses electric energy, and for high-carbon steel wire smelting, in the case of good scrap steel quality, the electric furnace can more efficiently melt scrap steel and perform refining. At present, in the process of producing high-quality wire by electric furnace short-process, due to the lack of appropriate monitoring and feedback measures, the electric furnace smelting process is in a black box state, and the electric furnace power supply is basically controlled by manual experience. Manual operation is difficult to accurately judge the electric furnace smelting state, resulting in problems such as long electric furnace power-on time, high smelting power consumption, poor end point temperature composition stability, and the like, which is not conducive to the stable control of product impurity elements, inclusions, and composition, etc.

[0044] To solve the above problems, the application provides a high-carbon steel wire short-process efficient and low-cost electric furnace automatic power supply method, a smelting process and a smelting system. On the one hand, the change of the electrode height in the electric furnace smelting process is dynamically monitored to feed back the melting state of the scrap steel in the furnace; on the other hand, the energy input model is established by analyzing the power-on influencing factors in the electric furnace smelting process; the electric furnace smelting stage is dynamically divided according to the results of the two aspects, and the voltage and current curves of each electric furnace smelting stage are set according to the division results, so as to realize the electric furnace smelting optimization power supply, shorten the power supply time and reduce the smelting power consumption.

[0045] In all settings, the biggest innovation of the application is to provide a high-carbon steel wire short-process efficient and low-cost electric furnace automatic power supply method, which is mainly used for the following steps after the molten iron is treated by the KR process:

[0046] Step S1, first confirm that the electric furnace loading is controlled at 115t-118t, and the molten iron ratio is controlled at 25%-50%; determine the weight of the scrap steel, the weight of the molten iron, the silicon content of the molten iron, the end composition of the smelted steel grade and the end temperature in the electric furnace process from the database; regarding the end composition and temperature of the smelted steel grade, for the steel grade of the application, the smelting end temperature is ≥1600℃, and the end composition includes: C>0.04%, P<0.012%, S<0.012%, N<50ppm in mass percentage.

[0047] The weight of the scrap steel and the molten iron is determined from the database of historical data, which helps to provide accurate reference for the batching of the electric furnace process according to the requirements and target output of different steel grades, and reasonably arrange the addition amount of scrap steel and molten iron. The end temperature and composition directly affect the performance of the steel. By comparing the differences between the actual production and the standard process requirements through these data in the database, the reasons for the quality fluctuation can be found in time, and the electric furnace end tapping temperature, the silicon content of the molten iron, and the end composition and temperature of the smelted steel grade are the key to ensure the product quality.

[0048] Regarding the scrap steel, based on the smelted steel grade of the application, the chemical composition of the scrap steel is ≤0.005% in mass percentage, including S≤0.005%, Ni≤0.01%, Cr≤0.03%, Cu≤0.01%, Al≤0.01%, Ti≤0.01%.

[0049] Since the purpose of the electric furnace smelting power optimization provided by the application is to provide energy to melt the scrap steel and increase the temperature of the molten steel, the three important factors affecting the overall energy balance are: the weight of the molten iron, the electric furnace end tapping temperature and the silicon content of the molten iron. Next step S2, the required power-on amount in the electric furnace process is calculated by the weight of the molten iron, the electric furnace end tapping temperature and the silicon content of the molten iron, and the calculation formula is

[0050] , is the power supply, unit: kWh, is the weight of molten iron into the furnace, unit: t , is the end point tapping temperature of the electric furnace, unit: ℃, is the silicon content of molten iron into the furnace, unit: %; The above energy model is obtained by linear fitting by least squares method. The basic idea of least squares method is to estimate the model parameters by minimizing the sum of squares of residuals between observed values and model predicted values. In electric furnace smelting, based on the relationship between the factors such as the weight of molten iron into the furnace, the silicon content of molten iron and the end point temperature and the power supply, the error between the predicted power supply value and the actual required power supply can be made as small as possible.

[0051] After the energy model is calculated, the required power supply of the current furnace is sent to the PLC, and the PLC controls the electrode to start the electric furnace smelting, i.e. step S3. The electric furnace starts smelting by changing the height of the electrode and combining the measured smelting power consumption. The electric furnace smelting process is sequentially divided into four periods, namely, the hole penetration period, the melting period, the temperature rising period and the temperature composition adjustment period. The power supply curve is set to adjust the voltage and current levels of the four periods.

[0052] Regarding the setting of the four periods, the time period from the start of power supply to the lowest point of electrode height is defined as the hole penetration period. The time period from the end of hole penetration period to the time period when the electrode maintains the same height is defined as the melting period. The time period from the end of melting period to the time when the power consumption is 85% of the required power supply is defined as the temperature rising period. The time period from the end of temperature rising period to the end of smelting is defined as the temperature composition adjustment period.

[0053] Because the power supply system required in different stages of scrap steel melting in the electric furnace smelting process is quite different, small voltage and large current power supply system is implemented in the hole penetration period to ensure rapid melting of scrap steel. In the melting period, after the molten pool liquid surface is formed in the furnace, maximum power is required for power supply, so large voltage and small current long arc is implemented. In the temperature rising period, after the scrap steel is completely melted, short arc operation is adopted to improve the arc energy utilization rate and ensure the temperature rising effect.

[0054] Preferably, during the piercing period, the transformer voltage gear adopts 10-12 gears, and the current gear adopts 5-7 gears; the secondary side voltage is controlled at 713V-835V, and the arc length is controlled at 478mm-512mm. During the melting period, the transformer voltage gear adopts 14-15 gears, and the current gear adopts 7-9 gears; the secondary side voltage is controlled at 871V-900V, and the arc length is controlled at 552mm-604mm. During the heating period, the transformer voltage gear adopts 13-14 gears, and the current gear adopts 8-9 gears; the secondary side voltage is controlled at 843V-871V, and the arc length is controlled at 529mm-562mm.

[0055] After entering the temperature composition adjustment period, the first temperature sampling is performed, the temperature T1 and the composition C1 are measured, and based on the end composition and the end temperature of the smelted steel determined in step S1, the power supply during the temperature composition adjustment period is adjusted according to the power supply curve, and the charging is also adjusted, specifically, the transformer voltage gear adopts 12-13 gears, and the current gear adopts 8-9 gears; the secondary side voltage is controlled at 815V-843V, and the arc length is controlled at 494mm-529mm, so that the end composition and the end temperature reach the tapping standard.

[0056] During the whole electric furnace smelting process, the oxygen consumption is controlled at 35-38Nm 3 / t, and the lime consumption is controlled at 30-35kg / t. Through the dynamic division of the electric furnace smelting stage, after setting the voltage and current curve of each electric furnace smelting stage, the optimized power supply of the electric furnace smelting is realized, which can quickly melt the scrap steel and perform refining, shortens the power supply time, improves the arc energy utilization, more efficiently melts the scrap steel and performs refining, and reduces the smelting power consumption. The application further provides a high-carbon steel wire short-process efficient low-cost smelting process based on the above electric furnace automatic power supply method. After adopting the electric furnace automatic power supply method, the following steps are continued:

[0057] Step S4, when the electric furnace is tapped to one-third, a low-nitrogen carbonizer is added, and metal manganese and low-titanium low-aluminum ferrosilicon are added for pre-deoxidization, and after tapping is completed, the ladle is lifted into the LF refining station for further adjustment of temperature and composition, and the molten steel temperature is controlled in the range of 1525℃-1535℃.

[0058] Step S5, after the composition adjustment is completed through step S4, soft stirring is performed to remove inclusions, and the argon blowing in the ladle is gradually reduced to the soft stirring state, and the reference flow rate is set in the range of 60NL / min-110NL / min, and the slag surface fluctuation is observed frequently in the early stage, and the soft stirring time is set in the range of 26min-31min.

[0059] Step S6, using a bloom continuous casting machine, the whole process of continuous casting protection, using low basicity low alumina tundish covering agent, control tundish steel superheat range is 20℃-30℃, using low melting point crystallizer protection agent, and using crystallizer electromagnetic stirring; Set the crystallizer water volume is 2975 L / min -3025L / min; Two cooling section adopts weak cooling mode, and set the two cooling section water volume 1 section is 60 NL / min -100 NL / min, 2 section is 20 NL / min -50 NL / min, 3 section is 20NL / min -40 NL / min, 4 section is 10 NL / min -30 NL / min.

[0060] Step S7, breakdown process, set the breakdown heating temperature range is 1180℃-1250℃, breakdown into 140mm*140mm.

[0061] Step S8, high line rolling process, heating temperature is 1080℃-1160℃, open rolling temperature is 960℃-1030℃, wire temperature is 860℃-920℃.

[0062] In the process of describing the method of automatic power supply of high-carbon steel wire short process high efficiency and low cost electric furnace, smelting process, another innovation point of the application is also included, which needs to dynamically monitor the change of electrode height in the electric furnace smelting process, especially for the smelting state of the four periods of wear period, melting period, temperature rising period and temperature composition adjustment period. Accurate judgment is needed. Obviously, artificial is impossible. Therefore, the application also provides a high-carbon steel wire short process high efficiency and low cost smelting system, which comprises an electrode, a rope encoder and an electric energy meter. The electrode is inserted into the electric furnace, and is fixed on the electrode cross arm through the electrode clamp at the same time. The electrode cross arm is drivenly connected with the electrode lifting hydraulic cylinder. The rope of the rope encoder is installed on the electrode hydraulic cylinder. When the electrode moves up and down in the ladle, the rope encoder can measure the height change of the electrode in real time. The electric energy meter is installed on the power supply line of the ladle, which can measure the current, voltage and power of the ladle, and then calculate the power consumption.

[0063] The following gives three embodiments of the application, to verify the feasibility of the high-carbon steel wire short process high efficiency and low cost smelting process provided by the application.

[0064] The molten iron in the furnace is subjected to KR desulfurization, the weight of the molten iron in the furnace is obtained from the database, the silicon content of the molten iron in the furnace and the electric furnace endpoint tapping temperature are obtained, as shown in Table 1.

[0065] Table 1

[0066]

[0067] Based on the data obtained from the database, the power consumption calculation formula is used to obtain the power consumption required for this furnace smelting, as shown in Table 2.

[0068] Table 2

[0069]

[0070] Based on the changes in electrode height and power consumption during the electric furnace smelting process, the electric furnace smelting stage is divided into the well drilling period, melting period, heating period and temperature composition adjustment period, and the voltage and current levels of the four periods are adjusted, as shown in Table 3 (Example 1), Table 4 (Example 2) and Table 5 (Example 3). The oxygen consumption during the electric furnace smelting process is controlled at 35-38Nm 3 / t, lime consumption is controlled at 30-35kg / t, and the molten iron ratio is controlled at 25%-50%.

[0071] Table 3

[0072]

[0073] Table 4

[0074]

[0075] Table 5

[0076]

[0077] The final tapping temperature of electric furnace smelting, and the final phosphorus, sulfur and nitrogen contents are shown in Table 6:

[0078] Table 6

[0079]

[0080] When the electric arc furnace is about one-third full of steel being tapped, a low-nitrogen recarburizer is added to the ladle, followed by metallic manganese for pre-deoxidation, and low-titanium, low-aluminum ferrosilicon. At the end of tapping, low-nitrogen recarburizer is added to the ladle, and the bottom-blown argon flow rate is controlled. The amounts of recarburizer and alloy added during the tapping process, as well as the amount of recarburizer added and the bottom-blowing control mode after tapping are complete, are shown in Table 7:

[0081] Table 7

[0082]

[0083] After entering the refining process, the remaining low-nitrogen recarburizer, metallic manganese, and low-titanium, low-aluminum ferrosilicon are added to adjust the composition. After the composition adjustment, the molten steel temperature is controlled within the appropriate range. Soft stirring is used to remove inclusions. The argon gas blowing from the bottom of the ladle is gradually reduced to a soft stirring state, and the soft stirring time is controlled. The recarburizer, alloy, molten steel temperature, soft stirring bottom blowing flow rate, and soft stirring time are shown in Table 8:

[0084] Table 8

[0085]

[0086] Then, the continuous casting process is entered, the continuous casting machine is a straight-arc rectangular billet continuous casting machine, the cross-sectional size of the continuous casting billet is 300mm*390mm, and the arc radius is 12.5m. The set continuous casting tundish pouring tonnage is 19t, the tundish tonnage is 35t in normal pouring, the tundish tonnage is 32t in continuous casting tundish changing, the tundish molten steel superheat is controlled to be 28 DEG C, the continuous casting speed is controlled to be 0.6m / min, and the sectional reduction amount, the reduction roller pressure, the mold powder layer thickness, the long nozzle argon flow, the mold electromagnetic current, the mold frequency and the mold water amount are as shown in Table 9.

[0087] Table 9

[0088]

[0089] The secondary cooling section adopts weak cooling mode, and the water amount of the secondary cooling section from zone 1 to zone 4 is respectively: zone 1 section 80 NL / min, zone 2 section 45 NL / min, zone 3 section 30 NL / min, and zone 4 section 25 NL / min. In the cogging and rolling process, the cogging heating temperature, the rolling heating temperature, the cogging temperature and the wire drawing temperature of 140mm*140mm are set as shown in Table 10:

[0090] Table 10

[0091]

[0092] From the above, it can be known that the steel scrap melting condition is dynamically monitored by the pull rope encoder, the electric furnace smelting stage is divided into the through hole period, the melting period, the temperature rising period and the temperature component adjusting period according to the steel scrap melting condition and the smelting power consumption condition, the voltage gear and the current gear of each stage are set according to the division of the electric furnace smelting stage, so that the precise and efficient control of the electric furnace smelting process is realized, the electric arc energy utilization is improved, the melting of the steel scrap is accelerated, and the smelting efficiency is improved.

[0093] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as such.

[0094] The meaning of "and / or" described in the present application means that each single existence or both existences are included.

[0095] The meaning of "connection" described in the present application can be direct connection between components or indirect connection between components through other components.

[0096] The above is the ideal embodiment according to the present application, and the above description can be changed and modified by the relevant personnel without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A high-carbon steel wire short-process, high-efficiency, low-cost electric furnace automatic power supply method, characterized by: After the molten iron has passed the KR treatment process, the following steps are continued: Step S1, determining from a database the weight of scrap steel fed into the furnace, the weight of molten iron fed into the furnace, the silicon content of the molten iron fed into the furnace, the end-point composition of the smelting steel grade, and the end-point temperature in the current electric furnace process; Step S2, calculate the amount of electricity required in the electric furnace process according to the weight of the molten iron entering the furnace, the final tapping temperature of the electric furnace, and the silicon content of the molten iron entering the furnace. The calculation formula is: ， is the amount of electricity supplied, in kWh, is the weight of molten iron in the furnace, in units of t , The final tapping temperature of the electric furnace is in °C. is the silicon content of the molten iron entering the furnace, unit is %; Step S3, start the electric furnace to start smelting, through the change of electrode height and combined with the measured smelting power consumption, the electric furnace smelting process is divided into four periods in sequence, namely, the well-penetrating period, the melting period, the heating period and the temperature component adjustment period, set the power supply curve, and adjust the voltage and current levels of the four periods; define the time period from the start of power-on to the electrode height dropping to the lowest point as the well-penetrating period, define the time period from the end of the well-penetrating period to the time when the electrode height remains unchanged as the melting period, and define the power consumption required from the end of the melting period to the power consumption reaching 85% The time period is defined as the heating period, and the time period from the end of the heating period to the end of smelting is defined as the temperature and composition adjustment period; After entering the temperature composition adjustment period, the first temperature measurement sampling is performed to measure and obtain the temperature T1 and the composition C1. Based on the endpoint composition and endpoint temperature of the smelting steel grade determined in step S1, the power supply during the temperature composition adjustment period is adjusted according to the power supply curve, and the feed is also adjusted so that the endpoint composition and endpoint temperature meet the steel tapping standards. The smelting endpoint temperature is ≥1600°C. Calculated by mass percentage, the endpoint components include: C>0.04%, P<0.012%, S<0.012%, and N<50ppm.

2. The high-carbon steel wire rod short-process, high-efficiency, low-cost electric furnace automatic power supply method according to claim 1, characterized in that: During the drilling period, the transformer voltage gear uses 10-12 gears, and the current gear uses 5-7 gears; the secondary side voltage is controlled at 713V-835V, and the arc length is controlled at 478mm-512mm.

3. The high-carbon steel wire rod short-process, high-efficiency, low-cost electric furnace automatic power supply method according to claim 1 is characterized by: During the melting period, the transformer voltage gear adopts 14-15 gears, and the current gear adopts 7-9 gears; the secondary side voltage is controlled at 871V-900V, and the arc length is controlled at 552mm-604mm.

4. The high-carbon steel wire rod short-process, high-efficiency, low-cost electric furnace automatic power supply method according to claim 1, characterized in that: During the heating period, the transformer voltage gear adopts 13-14 gears, and the current gear adopts 8-9 gears; the secondary side voltage is controlled at 843V-871V, and the arc length is controlled at 529mm-562mm.

5. The high-carbon steel wire rod short-process high-efficiency and low-cost electric furnace automatic power supply method according to claim 1 is characterized in that: During the temperature component adjustment period, the transformer voltage gear adopts 12-13 gears, and the current gear adopts 8-9 gears; the secondary side voltage is controlled at 815V-843V, and the arc length is controlled at 494mm-529mm.

6. The high-carbon steel wire rod short-process high-efficiency and low-cost electric furnace automatic power supply method according to claim 1 is characterized by: In step S1, the chemical components of the scrap steel fed into the furnace, expressed in mass percentage, include S≤0.005%, Ni≤0.01%, Cr≤0.03%, Cu≤0.01%, Al≤0.01%, and Ti≤0.01%.

7. The high-carbon steel wire rod short-process high-efficiency and low-cost electric furnace automatic power supply method according to claim 1, characterized in that: In step S1, the electric furnace charging amount is controlled in the range of 115t-118t, and the molten iron ratio is controlled in the range of 25%-50%.

8. The high-carbon steel wire rod short-process high-efficiency and low-cost electric furnace automatic power supply method according to claim 1, characterized in that: In step S3, the oxygen consumption range of the electric furnace smelting process is 35-38Nm 3 / t, lime consumption range is 30-35kg / t.

9. A short-process, high-efficiency, low-cost smelting process for high-carbon steel wire, characterized by: After adopting the electric furnace automatic power supply method according to claim 1, continue with the following steps: Step S4, when the electric furnace has tapped one-third of the steel, a low-nitrogen recarburizer is added, and a deoxidizer is added for pre-deoxidation. After tapping is completed, the ladle is hoisted into the LF refining station for further adjustment of temperature and composition, and the temperature range of the molten steel is controlled; Step S5, after the composition adjustment is completed in step S4, the argon gas blowing at the bottom of the ladle is reduced to a soft stirring state to remove inclusions; Step S6: Casting is performed using a bloom continuous casting machine, with full protection during the continuous casting process. The secondary cooling section adopts a weak cooling mode, and the water flow of the secondary cooling section is set to 60 NL / min-100 NL / min in section 1, 20 NL / min-50 NL / min in section 2, 20 NL / min-40 NL / min in section 3, and 10 NL / min-30 NL / min in section 4. Step S7, blanking process, blanking into 140mm×140mm; Step S8, high-speed wire rolling process.

10. The high-carbon steel wire rod short-process, high-efficiency, low-cost smelting process according to claim 9, characterized in that: In step S4, the added deoxidizers include metallic manganese and low-titanium, low-aluminum ferrosilicon. After the composition adjustment is completed, the temperature of the molten steel is controlled to be in the range of 1525°C-1535°C; In step S5, the flow rate of the ladle bottom blowing argon is set in the range of 60NL / min-110NL / min, and the soft stirring time is set in the range of 26min-31min; In step S6, during the continuous casting process, a low-basicity, low-alumina tundish covering agent is used, the superheat of the molten steel in the tundish is controlled within the range of 20°C-30°C, a low-melting-point mold powder is used, and electromagnetic stirring is used in the mold; the water flow in the mold is set to 2975 L / min-3025 L / min; In step S7, the heating temperature range for blanking is set to 1180°C-1250°C; In step S8, during high-speed wire rolling, the heating temperature is 1080°C-1160°C, the rolling start temperature is 960°C-1030°C, and the spinning temperature is 860°C-920°C.

11. A high-carbon steel wire rod short-process, high-efficiency, low-cost smelting system, characterized by: Used in the high-carbon steel wire short-process high-efficiency and low-cost electric furnace automatic power supply method according to claim 1, comprising electrodes, a pull-wire encoder and an electric energy meter; The electrode is fixed to the electrode cross arm through the electrode clamp. The electrode cross arm is connected to the electrode lifting hydraulic cylinder. The rope of the rope encoder is installed on the lifting hydraulic cylinder. When the electrode moves up and down in the electric furnace, the rope encoder can measure the height change of the electrode in real time. The electric energy meter is installed on the power supply line of the electric furnace. It can measure the current, voltage and power when the electrodes are energized, and then calculate the power consumption.

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